Improved method of extracting- gold and silver from their ores



it'd

JOHN TUNBRIDGE OF NEWARK. NEW JERSEY.

Letters Patent N 0. 85.258, dated December 22, 1868.

I ImROVEID METHOD.OP EXTRACTING- GOLD AND SILVER PROM THEIR ORES.

The Shedule'refen-ed to in these Letters Pategt and making part of the same.

To all whom it may concern:

, Be it known that 1, JOHN TUNDRIDGE, of -the city of Newark, in the county of Essex, and State of New Jersey, have invented an Improved Method of EX- tracting Gold and Silver from their Ores, possessing the advantage of bringing about the chemical change necessary for their eiiective amalgamation, with a great economy in time'and materials over other systems now in use. Also, a method of treating refractory or re-' belde ores, containing lime and earthy carbonates, ox-. ides, and metallic carbonates.

Description.

Formula. 1.

. With oueton of the above-named ores, ground sufficiently fine, and of the proper consistence, placed in the pateo or paved yard, incorporate three pounds of salt and two pounds of sulphate of copper, prepared in the following manner:

Dissolve the salt and sulphate of copper in separate wooden utensils, with as little water as may be necessary for the purpose; mix the copper with the salt, and thoroughly incorporate the whole. On the fol-v lowing day make a composition of metallic mercury, copper, and chloride of soda, as follows:' Take eight ounces of salt and eight ounces of sulphate of copper-,- dissolve to supersaturation, and mix them together.

Of mercury, squeeze through a cloth eight times the weight of the silver known to be contained in the ores,

stirring gently a little at a time. When the mercury loses most ofits metallic appearance, the whole is incorporated. From three to five daysafier this operation, according to the state of the weather, incorporate four pounds of sulphate of copper, and continue the process in the usual way until finished, When magistral, or pyrites of copper, are used instead of sulphate of copper, the pyrites must be calcined in a reverberatory furnace, in the usual manner. cooling, mix well eight pounds of salt with twenty-five pounds of magistral, gradually raising the temperature until it attains a dull red heat, mixing and keeping it well turned over, about two hours being generally required for this last operation. When cold, it is ready for use, and in this state the action of the atmosphere will not c'ause'it to deteriorate. With one ton of the lama or ground ores, prepared for receiving the reducing-materials, incorporate eight pounds ofthe magistrai, calcined as above, providing it contains thirty or thirty-three per cent. of sulphate of copper, sulphate of copper being preferable for making the composition. of metallic mercury and salt. After the expiration of a few days, incorporate ten pounds of I After soda, dissolved in water, leaving it in contact forafew days, and proceed as with docile ores, In extracting gold by amalgamation, I use the deoxidizing-materials, as hyposulphate of soda-and potash, the cyanides, 85c,

in conjunction with mercury; also, the composition of salt, sulphate of copper, and mercury, which I prefer, and use in the following manner: With one ton of the ground ore ready to be operated upon, I incorporate the usual quantity of the composition of salt, mercury, and sulphate of copper, as before directed, allowing this combination about one-third of the time usually taken for extraction. I then incorporate three pounds of sulphate of copper, or eight pounds of magistral,-and continue us usual. If iron pans or iron mar chinery be used in reducing, a less quantity of the lnagistral, or sulphate of copper, will he required. In amalgamating gold-ores containing carbonate of lime or metallic carbonates, and oxides of the inferior metals, I prefer the use of hyposulphate of soda, two pounds to the ton of ore, in conjunctiopwith mercury, and combinedin the usual way. Inthe extraction of gold by cyanides, I incorporate with oneton of the ore one pound of cyanide of potash, with the usual quantity of mercury, keeping it revolving in closed barrels, or other suitable vessels.

Explanatory Notes.

The mutual decomposition of ,thechloride of soda and sulphate of copper, previous to incorporation, is for the purpose of effecting a better interchange of elements than would take place if they were mixed with the great mass of ores. The combination of the salt, copper, and mercury causes them to react better together than they would if disseminated in the great mass of ores.

The object of incorporating the calcined pyrites and sulphate ofcopper, after the composition, is for the purpose of creating an electro-chemical agency, the hydrogen combining with the chlorine of the mercury formed in the process. and copper and the oxygen forming the oxide of copper.

Having thus described niy invention,

What I claim new, and desire to secure by Let-. ters Patent, is-

l. The method of combining metallic mercury, salt, or chloride of soda; and sulphate of copper, substantially as and for the purpose set forth.

2. The application and use of sulphur and its salts,

. substantially as and for the purpose set forth.

3. The application and use of the cyanides, tor the I extraction of gold, substantially as and for the purpose set forth.

JOHN TUNBRIDGE. Witnesses:

. -H.--C '.-G.0v1mr, Jnmns PERRY. 

